B.2.3 - 907-09-11 Congress Ave - Structural Letter — original pdf

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April 23, 2021 Ms. Donna Carter Carter Design Associates 817 W. Eleventh Street Austin, Texas 78701 RE: 907, 909 and 911 Congress Avenue - Historic Façades Dear Ms. Carter: At your request I visited the above-mentioned locations to observe and to provide a rendered opinion regarding an approach toward salvaging the historic fabric of the existing buildings facing Congress Avenue. The three masonry and wood framed structures were constructed in the early 20th century and have experienced a myriad of uses and modifications throughout their history. For the purposes of this report, we will be limiting our attention to the front elevations. It is my understanding that a significant development is planned for these sites, but the historic nature of the façades will need to be maintained. I have been charged to render an opinion for the historic rehabilitation based on the current structural integrity and the options associated with achieving the intended goal. Existing Condition The three structures have been vacant and have not been maintained for many years. As such the buildings have become dilapidated and have been exposed to the elements for quite some time. The existing wooden framed roof and upper floor systems are damaged extensively and have created a life/safety concern. The original masonry walls that divide the buildings are for the most part in acceptable condition. The existing main level slabs appear to be performing adequately. The existing façades are quite damaged and in need of extensive repair. Supporting steel beams are very old and compromised and are exhibiting signs of excessive deflection. Exposure has also contributed to their loss of structural integrity. Options It is my understanding that two options are being weighed for the rehabilitation of the building fronts. 1. Repair the elevations in-place. 2. Remove the existing materials and replace them in a historically appropriate fashion during or after the completion of the development. Based on the significance of the proposed development and the extensive effort required to protect an already compromised elevation, it is the opinion of this office that the existing materials should be removed and replaced at a more appropriate time in the development’s schedule. Firm No: F-3323 1018 W. 11th Street, Ste. 100, Austin, TX 78703 T: 512.499.0919 F: 512.320.852 www.structurestx.com  If option 2 is indeed executed, a very comprehensive cataloguing of the in-place assemblies will be required. Scaffolding will be required at the interior and exterior of the building to properly support scanning equipment, workers and the loads associated with the dismantling of the façades. Scaffolding Exterior scaffolding will be required to support the mentioned loads as well as to offer safe pedestrian traffic below. A scaffolding company familiar with this type of work will need to be commissioned. All scaffolding must be free standing and not depend on the existing structure for bracing. Interior scaffolding will be required to support the described loads. Although the foundation is adequate to support the anticipated loads, the upper levels are not. All scaffolding will need to be free standing and “threaded” through the existing second level and roof. All scaffolding will need to be continuous to the top of the structure. Please be aware that the floor and roof cannot be removed in its entirety as it currently provides bracing for the front elevation. The amount of bracing required for the front facade and the layout of the proposed scaffolding will require coordination to properly maintain structural integrity. Requirements for scanning, weight limits and allowable deflections in the scaffolding must be coordinated with all affected parties. Scaffolding may be removed upon completion of the dismantling of the front elevations. Replacement Prior to the replacement of the materials, appropriate structural steel framing must be provided to provide sufficient strength and stiffness. I am happy to expound on any aspect of this summary. Please let me know if you have any questions. Sincerely, Jerry Garcia, P.E. License #67435 Firm No: F-3323 1018 W. 11th Street, Ste. 100, Austin, TX 78703 T: 512.499.0919 F: 512.320.852 www.structurestx.com